(30 days)
The ergo Imaging System is intended to image the distribution of radionuclides in the body by means of a photon radiation detector. In so doing, the system produces images depicting the anatomical distribution of radioisotopes within the human body for interpretation by authorized medical personnel.
The proposed changes involve modifications to the 2020tc Imaging System to increase size of the detector head field of view (FOV) from 8"x 8" to 12"x 15". Modifications include mechanical and electrical design changes to support the large field-of-view (LFOV) detector head. The modified device (ergo Imaging System) incorporates Digirad's solid-state RIM detector design, modified with 3mm size pixels required for general purpose planar imaging. The 2020tc Imager detectors currently utilize the same 3mm pixel size.
The detectors used in the modified and predicate device utilize a pixelated, multi-crystal CsI scintillator detector with each pixel optically coupled to a low noise photodiode array. The charge detected from each gamma ray is amplified and processed using an amplifier circuit. The RIM detector design technology is currently used in the Digirad Cardius XPO imager systems with a 6mm pixel size for Cardiac SPECT imaging. The RIM detector has been modified to incorporate a 3mm size pixel required for general planar imaging. The RIM detector design includes electrical and mechanical configurations allowing for field replacement of detector modules and improved system performance (better energy resolution). The updated design of the RIM detector head assembly allows some of the current sub-systems to be moved into the detector head assembly (air dryer) and simplification of others (cooling and power distribution systems).
The modified device uses the 2020tc Imaging System SeeQuanta Acquisition software, with minor modifications required for use with the 3mm pixel size RIM detector modules.
The 2020tc Imager was initially marketed as the Digirad Notebook Imager (K961104), then re-branded as the 2020tc Imaging System (K982855) when it was used in conjunction, with the SPECTour Rotating Chair to obtain SPECT images in patients who are seated in an upright position. The modified device (ergo Imaging System) is a general purpose Nuclear Medicine Imaging device used for planar imaging, the same as the Notebook Imager/20201c Imager when imaging without the rotating chair.
The provided text describes a 510(k) premarket notification for the "ergo Imaging System," a scintillation (gamma) camera. The submission focuses on demonstrating substantial equivalence to predicate devices, rather than a standalone clinical study proving specific acceptance criteria in terms of diagnostic performance metrics like sensitivity or specificity.
Here's an analysis of the provided information based on your questions:
1. Table of acceptance criteria and the reported device performance
The document does not specify quantitative acceptance criteria for diagnostic performance (e.g., sensitivity, specificity, accuracy) that are typically reported for AI/algorithm-based devices. Instead, it focuses on demonstrating functional equivalence and meeting design specifications compared to predicate devices. The acceptance criteria essentially revolve around the system performing as per its specifications, which are similar to the predicate device's functional specifications, and not raising new safety or effectiveness concerns.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Functions as per specifications | All tests passed with actual results substantially matching expected results. System meets design specifications. |
| Similar functional specifications to predicate devices | Design specifications are similar to predicate device functional specifications. |
| Equivalent efficacy to predicate devices (no new safety/effectiveness questions) | Digirad internal testing and phantom images demonstrated equivalent efficacy to predicate devices, and did not raise new questions regarding safety and effectiveness. |
| Substantially equivalent to predicate devices (intended use, technology, overall system performance) | Testing results demonstrate the ergo Imaging System meets specifications and is substantially equivalent based on comparisons of intended use, technology, and overall system performance. |
2. Sample size used for the test set and the data provenance
The document does not explicitly mention a "test set" in the context of diagnostic performance (e.g., a set of patient images for evaluation). The testing described is primarily internal verification and validation of the system's technical specifications and phantom images. Therefore, details like data provenance or sample size for a diagnostic test set are not provided.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not applicable. The document describes technical testing and phantom images, not a clinical study involving experts establishing ground truth for diagnostic accuracy.
4. Adjudication method for the test set
Not applicable, as no diagnostic test set is described.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
No MRMC study is mentioned. This device is a gamma camera, a hardware imaging system, not an AI-assisted diagnostic software.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This is a hardware device; the concept of "standalone performance" for an algorithm doesn't directly apply in the same way it would for AI-driven software. The "system meets design specifications" and "equivalent efficacy to predicate devices" with phantom images represent its standalone performance relative to its intended function.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The document refers to "phantom images" and "Digirad internal testing." This implies the "ground truth" for the testing was based on known properties of the phantoms and the expected technical performance of the imaging system. There is no mention of clinical ground truth like pathology or outcomes data.
8. The sample size for the training set
Not applicable. This document describes a hardware device submission, not a machine learning algorithm that requires a training set.
9. How the ground truth for the training set was established
Not applicable, as no training set is described.
§ 892.1100 Scintillation (gamma) camera.
(a)
Identification. A scintillation (gamma) camera is a device intended to image the distribution of radionuclides in the body by means of a photon radiation detector. This generic type of device may include signal analysis and display equipment, patient and equipment supports, radionuclide anatomical markers, component parts, and accessories.(b)
Classification. Class I (general controls).